I'm currently in my second year of growing hops, with two Magnums and two Mt. Hood. My Magnum rhizomes were larger and stronger, and threw up tons of shoots this year. I trimmed back to about six per plant, and they grew pretty quickly to about six feet. Now they've stagnated for over a month and the tips of the shoots have dried up and turned brown, at least on the Magnums. The Mt. Hoods still seem to be okay. We have had a warm spell recently, but I noticed the browning tips before the really hot weather hit. Any idea what could be wrong? I'm assuming there won't be any more vertical growth from these shoots.